Whenever I am adding a new node to an already setup site, I am not able to get the Failover Candidate option when setting up. Thus I am not able to include the node as a Failover candidate. Please help.

In QMC Start >> Service Cluster >> Persistence Mode >> Single QVF is selected. What does this Persistence mode mean and how many Persistence modes are present?

Sorry to say but the information I seek isnt there. It only has the information of what a failover node is but what I want is to know that why can't I see the Node Configuration >> Failover candidate check box option when trying to setup a new node?

What are the different Failover node roles?

What does Persistence Mode mean and how many types of such modes are there?

Please find below the Qlik Sense version 3.2 details used in our site and let me know whether it supports Failover Candidate or not. But, as per the Qlik help site I think it does support Failover candidate. If it supports then why am I not getting the Node configuration > Failover Candidate option when trying to create a new node?